Operative Dentistry - Best Practices
(last modified August 5, 2014)
Excellent field control is necessary for long-term success of any dental restoration. It is especially important for any restoration which is adhesively bonded. The choice of field control technique is influenced by a number of factors, some of which are in the practioners’ control. Factors such as tooth size, shape and position; tissue position and health, lesions position and size; patient facial anatomy; and patient cooperation all influence the choice and effectiveness of field control. Whatever the choice of field control technique, the key is to have achieved isolation. Any isolation technique, including a rubber dam, must be properly placed to be effective. Isolation is critical in every area of the mouth. Adequate field control in the anterior segment is just as critical as it is in the posterior segments of the mouth.
Rubber Dam placement is the gold standard for field control. Evidence in the literature supports that when using a rubber dam higher quality restorations are produced, more efficient dentistry is accomplished and patients prefer the rubber dam. Additionally, the patient’s exposure to bio burden form the restoration removal and placement is reduced with a rubber dam. The dam must be placed using punch holes that are the appropriate size and properly placed. A rubber dam clamp that can be positioned on the tooth in a stable position and not impinge on adjacent tissues is the foundation of a good rubber dam. The use of a rubber dam napkin is recommended for patient comfort. Adjuncts to isolation including stabilizing cords and ligatures offer excellent supplements for superior isolation. Additional retainers (eg. 212/butterfly) may also be employed to help isolate class V lesions.
LIP AND CHEEK RETRACTORS:
Lip and cheek retractors (eg. Optragate, Expandex) are viable alternative methods of isolation when a rubber dam is not possible. These are used most often for isolation in the maxillary anterior segment. The use of cotton rolls under the maxillary lip in addition to the retractors adds lip retraction and supplemental isolation. Use of a gauze on the lingual aspect of the maxillary anteriors helps to keep the tongue away from preps during bonding and restoration.
COTTON AND COTTON ROLL HOLDERS:
Isoshields and cotton rolls may be used when a rubber dam or lip and cheek retractors are not possible. The appropriate size isoshield will adhere to the buccal mucosa, absorbing fluids and not impinge on the depth of the vestibule. Cotton roll placement on the buccal and lingual during restoration placement aids in maintaining a dry field. Cotton roll holders are an adjunctive means of filed control. They can be added to help hold cotton rolls in place during restoration Saliva evacuation placement in the distal portion of the treatment segment is advantageous to remove moisture from the field.
Additional aids to field control:
- Isolite is an excellent adjunct to field control when rubber dam placement is not possible. Use of this technique is limited in our clinics due to lack of availability.
- Hygroformic saliva evacuation is helpful in positioning the saliva evacuator to remain in place and remove moisture more effectively.
- Retraction cord and hemostatic agents – note that hemostatic agents may negatively affect adhesive bonding to tooth structure.